Combine sugar, milk, syrup, butter, and orange rind in a medium- size non-aluminum saucepan. Cook over medium heat, stirring constantly, until sugar dissolves. Cover and continue to cook over medium heat 2 to 3 minutes to wash down sugar crystals from sides of pan. Uncover and cook, stirring frequently, until mixture reaches soft ball stage (238°).
Remove from heat; cool to lukewarm (110°). Add orange juice and extract. Beat with a wooden spoon 2 to 3 minutes or until fudge thickens and begins to lose its gloss.
Pour fudge into a buttered 8- inch square baking pan. Mark top of warm candy into 1-inch squares, using a sharp knife. Cool completely before cutting. Store in airtight containers.